1. Field of the Invention
The present invention relates to a speech recognition apparatus and a speech recognition method suitably applied to a navigation apparatus mounted to e.g., a car for displaying a road map, etc., the navigation apparatus and a navigation method combined with this voice recognition apparatus, and a car for mounting these apparatuses thereon.
2. Description of the Prior Art
Various kinds of navigation apparatuses mounted onto a car, etc. have been developed. Each of these navigation apparatuses is constructed by a large capacity data memory means such as a CD-ROM storing e.g., road map data, a detecting means for detecting the present position of the car, and a displaying apparatus for displaying a road map in the vicinity of the detected present position on the basis of data read from the data memory means. In this case, the detecting means of the present position is constructed by using a position measuring system using an artificial satellite for a position measurement called a GPS (Global Positioning System), a self-contained navigation following up a change in the present position from a starting spot point on the basis of information such as a vehicle's running direction, a vehicle's running speed, etc.
A map displayed in the displaying apparatus is set such that a map in a desirable position can be displayed as well as the present position by performing a key operation, etc. as long as map data are prepared.
In the case of such a navigation apparatus, for example, in the case of the navigation apparatus for a car, the displaying apparatus is generally arranged in the vicinity of a driver seat such that a driver can see a map in the vicinity of the present position while the car is running and temporarily stops as in traffic signal stoppage, etc.
It is necessary to be able to operate such a navigation apparatus such that no navigation apparatus obstructs driving of the car, etc. For example, the navigation apparatus is constructed such that a complicated operation of the navigation apparatus is inhibited during the car driving. Namely, when such a navigation apparatus is arranged in a vehicle, the navigation apparatus is connected to a certain running state detecting section (e.g., a parking brake switch of the car). The navigation apparatus is set such that all operations of the navigation apparatus can be performed only when stoppage of the vehicle is detected by this running state detecting section, and a complicated key operation is inhibited in a nonstopping state (namely, during running of the vehicle).
However, it is inconvenient that no operation for switching display maps, etc. can be performed during such running. Accordingly, it is required that a high grade operation of the navigation apparatus can be performed without obstructing the driving of the vehicle even when the vehicle is running.
In such a case, it is considered that, for example, various kinds of commands are inputted by a speech input to operate the navigation apparatus. However, when incorrect commands are inputted through speech, etc., it is necessary to perform an operation for canceling the input by a key operation, etc. making it inconvenient to handle the navigation apparatus.